Cap forming apparatus with edge reforming control device



Feb. 12, 1952 F. sclBELLl 2,585,047 y CAP FORT/11N@ APPARATUS WITH EDGE REPORT/[TNG CONTROL DEVICEI Filed-March 4, 1948 ZT. Z1 f 3'] g Z9 f 44 Z /7 5g* 34 ZZ 3 D L# 5./ Z5 y 5c? k Z`- l 22s Jf//r ff g jj/ 4Z l? Z? j 77 7% '7| /7 y 625 E i 3 6 55 39 ZZ jg if. `l

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f B 5-2 M MN .D i L ATTORNEY5 Patented Feb. 12, 1952 CAP FORMING APPARATUS WITH EDGE REFORMING CONTROL DEVICE Frank Scibelli, Brooklyn, N. Y., assignor to American Can Company, New York, N. Y., a corporation of New Jersey Application March 4, 1948, Serial No. 13,004

6 Claims.

The present invention relates to an apparatus for forming sheet metal caps and has particular reference to devices for controlling the reforming of a projecting edge of such caps.

In the forming of sheet metal caps, it is sometimes advantageous to curl the projecting edge so that it will be smooth and uniform. However it has been found that variable factors such as the thickness of the metal plate from which the cap is made, ductility and other characteristics of the plate greatly affect the curl and result in variations in certain over-al1 dimensions of the cap. The more easily the plate can be bent the more curl is usually formed. Hence where it is desirable or necessary to maintain a definite dimension of the cap, for example its over-all height, it is also necessary to control the amount of curl, regardless of the thickness of the plate or its ductility or other variable characteristics.

The instant invention contemplates overcoming these difficulties by providing in a die mechanism for forming a cap or other dish shaped article, devices for controlling the amount of projecting flange or curl formed on the cap or article.

An object of the invention is the provision in a sheet metal cap forming apparatus, of devices wherein the reforming of a projecting edge of a cap may be controlled in such a manner -as to control a predetermined over-all dimension of the cap.

Another object is the provision of such a cap forming apparatus wherein the controlled reforming of the projecting edge of -a cap may be eiected as an incident to the forming of the cap.

Another object is the provision in a sheet metal cap forming die mechanism of devices wherein the pressure on the draw ring of the die mechanism during its return stroke is controlled in such a manner as to control the amount of curling of the projecting edge of a drawn cap so that control over the over-all height of the cap may be effected regardless of the thickness or ductility or other quality of the plate from which the cap is made.

Numerous other objects and advantages of the invention will be apparent as it is better understood from the following description, which, taken in connection with the accompanying drawings, discloses a preferred embodiment thereof.

Referring to the drawings:

Figure 1 is a vertical sectional view taken of the apparatus illustrated in Fig. 1, showing different positions of parts of the forming apparatus during different stages of formation of the cap and the reforming of its projecting edge; and

Figs. 4 and 5 are enlarged fragmentary tr-ansverse sections of a cap produced in the forming apparatus shown in Fig. 1, the two views showing diiferent stages in the forming of the cap.

As a preferred embodiment of the instant invention the drawings illustrate a die mechanism for first cutting a disc from -a strip A of sheet metal (Fig. 1) and then drawing the disc into a cap shell B (Fig. 4) having a surrounding wall or skirt section C terminating in a projecting edge D. Following the drawing action the projecting edge D is formed with an edge curl E (Fig. 5).V

The cap is then ejected from the mechanism. It will be obvious that the step of cutting may be eliminated and a previously formed disc blank or a preformed cap having a projecting edge to be reformed may be used in the first instance.

The apparatus disclosed for the Purpose 0f illustrating the invention is embodied in a standard form of press and comprises a die shoe or plate 2| (Figs. 1, 2 and 3) which is mounted on a press bed or bolster plate in the usual or preferred manner. The die shoe 2| supports an annular die cutedge 22. The cutedge is secured to the shoe by bolts 23'(Fig. 1)

Cutting and forming ofthe cap B from the strip A of sheet material is effected by a pair of opposed, substantially concentric, annular instrumentalities having a forward and return movement Iand which comprise a conventional reforming or curling ring 25 disposed within the cutedge 22 and a vertically reciprocable conventional punch 26 disposed above and in alignment with the curling ring. The punch is carried in the usual manner as by a slide member which moves up and down above the die parts. This slide member forms no part of the novelty of theI instant invention and illustration and further description is therefore omitted.

The lower end of the punch 26 is hollow and carries therein an annular knockout 28. The

knockout is formed on a stem 29 which extends up through the punch and at its upper end carries a hardened cam shoe 3| located in a bore 32 formed in the punch. The cam shoe 3| extends above the punch and engages against a rotatable edge cam 33 which operates the knockout. A compression spring 34 coiled around the stem 29 and interposed between the cam shoe 3| and the punch 26 at the bottom of the bore 32 keeps the cam shoe in engagement with the cam 33.

The curling ring 25, disposed within the cutedge 22, surrounds an annular die center or anvil 3S which is supported on the die shoe 2l and securely held in place by bolts 31. The upper face of this anvil is located slightly below the upper edge of the cutedge 22.

In the'normal position of the curling ring 2: as shown in Fig. l, its upper face is flush with the upper edge of the cutedge 22. The ring is 'located in this position by a stop flange 38 which is formed on the ring and which engages against a shoulder 39 formed in the cutedge. Inthis position the curling ring is supported on the upper ends of a plurality of vertically disposed.

support or ejector pins 42- which extend down through the die shoe 2l and which at their lower ends are secured in a pin plate 43 located below the die shoe.

The pin plate 43 surrounds a threaded bolt 44 which -is secured in and which depends from the die shoe 2l. predetermined pressurel of` an ejector springV 45 ofl the compression. type, which surrounds thebolt andrwhich is interposed between theplate and; a pair of lock nuts 45- carried on. the bolt. The pressure of' the spring against thel platev may be adjusted by adjustment of the lock nuts 4B to effect a predetermined pressure on the curling ring 25.

In theoperation of the mechanism, tocut and form a cap B from the strip A of sheetv metal, the punch 26v moves down through a forward stroke against the strip and clamps it in a slip grip'against the curling ring 25. As'V the punch continues to 'move down through this forward stroke, it depresses the curling ring against the force'cf the spring 45 and cooperatesl with the cutedge 22 to cut through, the strip and thus sever a circular disc orblank therefrom. The outer marginal edge of thisblank is heldin the slip grip between the punch'and the curling ring. Theknockout 28 moves down with the punch and clamps the inner portion of the blank against the upper face of the anvil 36.

With continued forward movement of the punch, it further depresses the curling ring. 25l

and thereby draws or forms the blank overY the anvil-35 to form theside Wall or skirt C of the cap, the punch moving down over the anvil as shown in Fig. 2. Thus the cap is now disposed within the punch. This' drawing action is continued untilv the cap is fully formed and the lower edge of the punch has passed or is adjacent the terminal edge D of the cap. If desiredv this drawing action may be terminated just prior to the lower edge of the punch reaching the terminalv projecting edge of the cap so as to leavea slight flange or flare yon this-projecting edge.

During this forward stroke of the punch, the descending reforming or curling ring 25 engages against and depresses a plurality of reforming or curling pins l. through the die shoe 2| and at their lower ends are secured in a pin plate 52. The pin plate 52 rests on a conventional rubber or other resilient hollowY block 53 which surrounds the ejector spring 45. The block ishelcl in place by washers 54,- 55 and' lock nuts 56 carried on the lower end of the spring bolt 44. An initial compression of the rubber block 53 is made byadjusting the lock nuts 56.

Thus as the curling ring is forced down in the cutedge 22, it further compresses` the rubber blockl 53 beyond its initial compression and thereby sets upin the rubber considerable pressure whiclr'greatly exceedsthe strength ofthe ejector The plate is maintainedunder a These curling pins extend spring 45. At this point in the cycle of operation of the die mechanism, i. e. when the lower edge of the punch 25 is adjacent the terminal projecting edge D of the drawn cap B as shown in Fig. 2, the punch ceases its downward or forward movement and begins its upwardror return stroke. The knockout 28 during the forward stroke moves down into a position on top of the cap during the drawing operation and remains in this position to hold the cap on the anXil during the returnstroke of the punch.

During the return stroke of the punch 25 the projecting edgev D ofthe cap B is reformed to produce the edge curl E (Fig. 5) hereinbefore mentioned while the knockout 28 holds the cap in place on the anvil 36. For this purpose the inner, upper edge of the curlingl ring 25 is formed with a conventional curling recess or die 6l (Figs.

" the projecting edge D'into the edge curl E. (Figs.`

y anvil 36'. In this manner control may be had over the height dimension of the cap regardless 3 and 5). Y

Provision is made for limiting the-'curling action sol that. this action` will be stopped a.

predetermined distance from the top face of the of the thickness of thematerial from which? thel cap is made or the ductility of this material. Thus thisV height dimension may beY constantly maintained and allrcaps made'in this mechanism will be the same height.

This control of the amount of curling of the projecting edge D of the drawn cap is brought about by a stop element 53 which preferably isinterposed between the bottom of the die shoe 42i and the top face of the' pin plate 52 of the rubber 53. In the instant mechanism as disclosed` inthe drawings, the stop element 63- is in the form ofa sleeve or bushing. which surrounds the curling ring pins 5l. There is one bushing for each pin. The lower ends of the bushings are threaded and engage in a threaded bore 64 formed in the pin plate 52 so that the bushings may be adjusted vertically. A lock nut is provided on each bushing for locking the bushings in an adjusted position.

Thus the stop element bushings 53 may be adjusted to limit within a predetermined range, the upward travel of the pin plate 52 against the pressure of the rubber block 53 and hence through the pins-5l control theV curling action of the curling ring die 6l. As shown in Fig. 3 this limiting action is brought about by the upper end of the stop sleeve 63 coming into engagement with the bottom of the xeddie shoe 2|. This engagement stops further upward movement of the pin plate 52 and thepins 5l and thus the pressure of the rubber block 53 -becomes ineffective against the curling ring 25.

Since the ejector spring' 45 purposely-is made weaker than the available pressure of the rubber block 53 so that this spring can not continue the curling action, the forming of curl thus ceases when the stop elements E3 engagethe fixed die shoe 2l and the height of the capis thus maintained. However the ejector spring 45continues toV press the pins 42 against the bottom of the curling ring 25 and as. soon as the knockoutrZ releases its hold on the cap B and starts to move up with the punch', the ejector spring 45 further lifts the curling ring and thus ejects the nished cap from the anvil. The cap usually clings to thepunch and when the punch is high enough in its upstravel, the knockout operates to eject the cap from the` punch to any. suitable place of deposit.

"It is thought that the inventionV and many of its attendant advantages will be understood from the foregoing description, and it will be apparent that various changes may be made in the form, construction and arrangement of the parts without1 departing from the spirit and scope of the inventionor sacrificing all of its material advantages, thev form hereinbefore described being merely a preferred embodiment thereof.

l. In a cap forming apparatus, the combination of a die shoe, a support mounted on said die shoe for a cap having a projecting edge, a reforming and ejecting ring surrounding said support and movable relative thereto for engagement with the projecting edge of said cap, a plurality of pins slideable in said die shoe for supporting said ring, a reforming pin plate engageable with some of said pins, an ejector pin plate engageable with the other of said pins, a resilient member operating against said reforming pin plate and forcing said ring against said projecting edge for reforming it, a plurality7 of adjustable stop elements disposed between said die shoe and said reforming pin plate and limiting the travel of said ring toward the projecting edge of said cap under the action of said resilient member for limiting the reforming action on said projecting edge for maintaining a predetermined dimension of said can, and resilient means of a strength less than that required to effect a reforming action on the projecting edge of said cap and operating against said ejector pin plate and forcing said ring against said projecting edge for ejecting said cap from the apparatus after the reforming oi said projecting edge.

2. In a cap forming apparatus, the combination of a pair of opposed, substantially concentric punch and ring members having a forward and a return movement and clamping a disc positioned therebetween in a slip grip, an anvil coactive with said members during their forward movement for drawing said disc from Ibetween the slip grip of said members and into one of them. thereby shaping the disc into a cap having its edge left projecting, pressure means acting against said ring member during the return movement of said members and forcing said ring member against said projecting edge of said cap for reforming said edge, stop means controlling the action of said pressure means for controlling the reforming of s aid cap edge to maintain a predetermined height dimension of said cap, and auxiliary pressure means having a strength less than that required to reform the projecting edge of said cap and acting against said ring member during its return movement and forcing said ring member against said projecting edge for ejecting said cap from said anvil after the reforming operation.

3. In a cap forming apparatus, the combination of a die shoe, a support mounted on said die shoe for a cap having a projecting edge, a reforming and ejecting ring surrounding said suphaving sliding movement in said die shoe, said support` pins engaging and supporting said ring, a reforming pin plate located below said die shoe, reforming pins carried by said reforming pin i plate and having sliding movement in said die shoefor pressure engagement with said ring',`

means operating yagainst said reforming pin Plate and acting through said reforming pins for forcing said ring upward -a predetermined distance against said projecting cap edge to reform the same, and resilient means of a strength less thanJ that required to effect a reforming action on the projecting edge of said cap and operating against.y

said ejector pin plate through said support p ins forfurther forcing said ring upward against said projecting cap edge to eject said cap fromk the apparatus after the reforming of its'projecting edge.

4. In a cap forming apparatus, the combination of a die shoe, a support mounted on said die shoe for a cap having a projecting edge, a reforming and ejecting ring surroundingV said support and movable relative thereto for engagement with the projecting edge of said cap, an ejector pin plate located below said die shoe, ejector pins carried by said ejector pin plate and having sliding movement in said die shoe, said support pins engaging and supporting said ring, a reforming pin plate located below said die shoe, reforming pins carried by said reforming pin plate and having sliding movement in said die shoe for pressure engagement with said ring, pressure means operating against said reforming pin plate and acting through said reforming pins for forcing said ring against said projecting cap edge to reform the same, a plurality of stop sleeves mounted on said reforming pins between said die shoe and said reforming pin plate for terminating the travel of said ring under the action of said pressure means for limiting the reforming action on said projecting cap edge to maintain a predetermined dimension of said cap, and spring means of a strength less than that required to effect a reforming action on the projecting ,edge of said cap and operating against said ejector pin plate and through said ejector pins for lifting said ring and with it said reformed Vcap to eject the cap from said cap support after termination of the reforming action.

5. In a cap forming apparatus, the combination of a die shoe, a support mounted on said die shoes for a cap having a projecting edge, a reforming and ejecting ring surrounding said support and movable relative thereto for engagement with the projecting edge of said cap, a plurality of pins slideable in said die shoe for supporting said ring, a reforming pin plate engageable with some of said pins, an ejector pin plate engageable with the other of said pins, a resilient member operating against said reforming pin plate and forcing said ring upward against said projecting edge for reforming it, a plurality of adjustable stop elements disposed between said die shoe and said reforming pin plate and limiting the travel of said ring toward the projecting edge of said cap under the action of said resilient member for limiting the reforming action on said projecting edge for maintaining a perdetermined dimension of said cap, and means for lifting said ejector pin plate and the pins enaussen 7', gage@ therebyto.- further lift said ring tov eject the reformed cap from saidcapsupport.

6. In.. a cap forming apparatus, the combination. of a pair of opposed, substantially concentric punch and ring members having a forward and a return movement andclamping a disc positioned therebetween. in a slip-grip, a dieV shoe, ana-nvilmounted on said die shoe and coactive with said members during their forward. movement for drawing said disc from between the 1 slip. grip of saidv membersand intovone of them thereby shaping the disc into a cap having its edgeleft projectinga plurality of pins slideably mountedin said` die shoe and engaging said ring member, reforming pressure means acting against 1 said pins. during the return movement of said paired, members and forcing. said ring member against. said projecting edge of said cap for re.- forming said. edge,. and adjustable stop means on.- saidpinsv and engageable with said die shoe f oxtvlimiting the travel of said. ring member, un.-

den reformingv pressure for controlling the reforming of said cap edge to maintain .a predetermined height dimension of said cap, and ejecting pressure means acting against said. ring,

member for forcing said` ring member against.

said. reformedv edge for ejecting said cap from theanvil.

FRANK SCIBEILI.

REFERENCES CITED The following references-are of record` in the le of this patent:

UNITED STATES PATENTS Number Name Date 1,884,708 Jeneson Oct. 25,1932 1,904,920 Hothersall Apr. 181933 1,919,287 Auble July 25', 1933. 2,067,265 Ernst June 121937 2,331,490 Menkin Oct., 121943 

